Polymers with tertiary amine groups for drug delivery and bioimaging

Over the past decade, biopolymers have gained great interests especially in biomedicine due to their physical properties and/or chemical structures changes in response to external stimuli in a certain time fiarne or at a specific location. Among them, poly（β-amino ester）s, methacrylate-based block copolymers and polypeptide with tertiary amine groups have been extensively studied and exhibit pH sensitive properties due to the protonation of tertiary amine groups. The pH values in normal organs, tissues, and subcellular compartments are always different from those in pathological tissues. These interesting properties allow their applications in a variety of fields ranging from diagnosis and therapeutics of diseases. Here, we review the recent progress of poly（β-amino ester）s, methacrylate-based block copolymers and polypeptide with tertiary amine groups and their applications in drug delivery and bioimaging.